This invention relates generally to the field of surgery and, more particularly, to a method and devices for performing anastomoses. More specifically, the present invention relates to a method and devices for performing end-to-side vascular anastomoses utilizing transluminal approach with endoscopic assistance, including, performing end-to-side anastomoses between intact thoracic or abdominal arteries and diseased coronary arteries.
Anastomosis is the union or joinder of one hollow or tubular organ to another so that the interior of the organs communicate with one another. There are generally two types of anastomosis: end-to-end and end-to-side. In an end-to-end anastomosis, the severed end of a first hollow organ is coupled, usually by suturing or stapling, to the severed end of a second hollow organ. In an end-to-side anastomosis, however, the severed end of a first hollow organ is connected around an opening cut into the side of a second hollow organ.
Typically, anastomoses are performed between airways, blood vessels, bowels, and urogenital lumens. The procedure for connecting blood vessels is referred to as vascular anastomosis. One of the best known surgical procedures utilizing vascular anastomoses is the coronary bypass. In the context of coronary artery disease, the flow of oxygenated blood to the myocardium of the heart is inhibited by a stenosis or obstruction in the coronary artery. This flow can be improved by providing a coronary artery bypass graft ("CABG") between the aorta and a point in the coronary artery distal to stenosis. Typically, a section of vein from the leg is removed and attached at one end to the aorta and at the other end to the coronary artery utilizing end-to-side anastomoses. Such grafts are known as saphenous vein grafts. Alternatively, synthetic grafts can be utilized to effect the bypass.
While the typical coronary bypass procedure favorably affects the incidence and severity of angina in patients with coronary artery disease, a variety of risks are associated with such procedures. Among them are mortality, myocardial infarction, postoperative bleeding, cerebrovascular accident, arrhythmias, wound or other infection, aortic dissection and limb ischemia. Furthermore, the vein grafts deteriorate over time, thereby resulting in the recurrence of angina, myocardial infarction and death. In addition, the costs of such procedures are relatively high and the patient recovery relatively long.
In an attempt to overcome such problems, a number of alternative approaches have been developed. For example, artery to artery bypass procedures have been utilized in which an arterial source of oxygenated blood--such as the left internal mammary artery ("LIMA") or right internal mammary artery ("RIMA")--is severed and anastomosed to the obstructed coronary artery distally to the stenosis or occlusion. More recently, other arteries have been used in such procedures, including the inferior epigastric arteries and gastroepiploic arteries. In general, artery to artery bypass procedures have demonstrated a better patency rate as compared with autologous vein or synthetic grafts.
While vascular anastomoses can be effective, and sometimes life-saving procedures, traditionally available techniques have been associated with a number of complications. For example, conventional techniques for performing vascular anastomoses generally require an extensive incision in the patient's body. Such operations are traumatic to the patient, involve a lengthy recovery, and a relatively high risk of infection or other complications.
In the context of coronary bypass surgery, for example, the bypass graft or artery-to-artery procedure is traditionally performed using an open chest procedure. In particular, each procedure involves the necessity of a formal 20 to 25 cm incision in the chest of the patient, severing the sternum and cutting and peeling back various layers of tissue in order to give access to the heart and arterial sources. As a result, these operations typically require large numbers of sutures or staples to close the incision and 5 to 10 wire hooks to keep the severed sternum together. Furthermore, such procedures leave an unattractive scar and are painful to the patient. Most patients are out of work for a long period after such an operation and have restricted movement for several weeks. Such surgery often carries additional complications such as instability of the sternum, post-operative bleeding and mediastinal infection. Cutting through layers of the patients tissue may also severely traumatize the tissue and upset the patients emotional equilibrium. Above all, open procedures are associated with long recuperation times.
Due to the risks attendant to such procedures, there has been a need to develop procedures which minimize invasion of the patient's body tissue and resulting trauma. In this regard, limited open chest techniques have been developed in which the coronary bypass is carried out using an abdominal (subxyphoid) approach or, alternatively, a "Chamberlain" incision (an approximately 8 cm incision at the sternocostal junction), thereby lessening the operating area and the associated complication rate. While the risks attendant to such procedures are generally lower than their open chest counterparts, there is still a need for a minimally invasive surgical technique. Nevertheless, each of these techniques is thoracotomic, requiring an incision to be made in the chest wall through which conventional surgical instruments are introduced to perform conventional coronary bypass surgery.
In order to reduce the risk of patient mortality, infection, and other complications associated with surgical techniques, it is advantageous and desirable to utilize endoscopic and thoracoscopic surgical techniques. Such procedures usually involve the use of surgical trocars which are used to puncture the abdomen or chest, thereby facilitating access to a body cavity through the cannula and a relatively small opening in the patient's body. Typically, such trocars have a diameter of about 3 mm to 15 mm. Surgical instruments and other devices such as fiber optic cameras can be inserted into the body cavity through the cannula. Advantageously, the use of trocars minimizes the trauma associated with many surgical procedures.
When traditional vascular anastomoses are performed, it is desirable to effect a suitable leak-proof connection between organs. Typically, such connections are established using suturing techniques. It is significant to note, however, that suturing of vascular structures is a tedious and time consuming process. Furthermore, these suturing techniques are not readily adapted for to endoscopic techniques where the surgeon's freedom of access and movement are more limited. Thus, there is a need for an alternative to these suturing techniques that would expedite the procedure, and a further need for an alternative that can be readily adapted for endoscopic use.
Various stapling techniques are known for providing anastomotic connections between organs, such as in intestinal and colorectal anastomoses. Due to the size of these devices, however, they are not easily adapted for use with vascular organs or endoscopic techniques. Furthermore, such techniques typically require penetration of the organ wall. Thus, due to the increased likelihood of clotting associated with penetration of the interior of the vascular wall, these techniques have not found ready application to the vascular system.
Recently, a surgical procedure and surgical clip have been developed which are intended to facilitate the anastomoses of vascular structures. In this technique, the vascular tissues are approximated, partially everted, and then clipped by applying the arms of the surgical clip over the everted tissue and securing the clip so as to hold the tissue together without penetrating the interior wall of the vessel. Nevertheless, in order to properly utilize these clips, the tissues should be everted. It would be desirable if such clipping devices could be adapted for endoscopic use. Further, it would be desirable to eliminate the need for everting the tissue prior to application of the clips in order to facilitate endoscopic assisted anastomoses.
It should, therefore, be appreciated that there is a definite need for a method and devices for performing vascular anastomoses which minimize the risk of infection, trauma, and other complications associated with conventional surgery, and, in particular, a need for a device which can be utilized in conjunction with an endoscopic technique for vascular anastomoses. It will also be appreciated that there exists a need for methods and devices for performing vascular anastomoses utilizing endoscopic assistance in which the first hollow organ can be easily aligned and secured to the second hollow organ.